DNA fingerprinting of a national sample of Mycobacterium tuberculosis isolates, Botswana, 1995-1996.

DNA fingerprinting may be useful to elucidate tuberculosis (TB) transmission in community settings, but its utility is limited if only few fingerprint patterns are observed or band numbers are low. We performed DNA fingerprinting on a national, population-based sample of Mycobacterium tuberculosis isolates from Botswana. During 1995-1996, a random sample of 213 isolates, representing 5% of all smear-positive TB cases, underwent DNA fingerprinting using restriction fragment length polymorphism (RFLP) IS6110 analysis. Eighty-two (38%) of the 213 isolates belonged to one of 18 clusters, with 2-9 isolates/cluster. The median number of bands was 10 (range 1-19); 183 (86%) had six or more bands. Sixty-three (49%) of 128 patients tested were infected with the human immunodeficiency virus (HIV). The degree of RFLP pattern heterogeneity and high band number support the feasibility of a prospective DNA fingerprinting study in Botswana.

Survey of physician use of radiography and sputum smear microscopy for tuberculosis diagnosis and follow-up in Botswana.

SETTING: National survey of physician knowledge, attitudes, and practices for tuberculosis (TB) diagnosis and monitoring in Botswana. OBJECTIVE: To assess adherence to national guidelines for TB diagnosis and monitoring. DESIGN: Questionnaires were mailed to all physicians registered with the Ministry of Health. RESULTS: The response rate was 69%. Diagnostic and follow-up practices differed substantially from national recommendations. Senior District Medical Officers (SDMOs) were the most likely to adhere to guidelines on use of sputum examination for diagnosis (87%) and follow-up (50%); private practitioners were the least likely to follow the same guidelines (53% and 10%, respectively). SDMOs were also less likely to use radiographs for diagnosis (27%); the greatest use was seen in government hospital-based physicians (86%). While most SDMOs had received an introduction to the TB programme and had access to the programme manual and recent information on TB, the majority of other practising physicians in the country did not. CONCLUSION: Recommended diagnostic procedures for TB were not being followed by a substantial percentage of physicians. Efforts are being made to inform hospital-based physicians and private practitioners about TB programme policies. Adherence to programme recommendations is vital to strengthen TB control efforts.